Throwable Objects

ABSTRACT

Embodiments of the invention relate to throwable toys such as shuttles and balls. In some of the illustrative embodiments a shuttle includes means to determine information relating to the throw or state of motion of the shuttle, and means to convey an audio information signal to a user during the throw.

FIELD OF THE INVENTION

This invention relates to throwable objects. Illustrative embodiments of the invention relate to throwable toys such as shuttles and balls. In some illustrative embodiments a shuttle includes means to determine information relating to the throw or state of motion of the shuttle, and means to convey an audio information signal to a user during the throw.

BACKGROUND OF THE INVENTION

It is known to play a variety of games using throwable objects such as shuttles, football and vortex footballs. More recently, such throwable objects have incorporated on-board electronics to measure and display information such as the distance travelled by the ball, for example using an accelerometer in combination with a microprocessor as disclosed by U.S. Pat. No. 5,779,576. US 2008/0234077 discloses a ball comprising a motion switch that emits a sound at different intervals when passed from player to player to indicate to the players a stage of the game, e.g. when playing “hot potato”.

However existing electronic balls are limited in terms of the flight information they can accurately generate in relation to the distance, height and speed that the ball is thrown. For example, an accelerometer is not able to distinguish between motion of a ball in the hand and motion of a ball through the air. When a swing is given to a ball by a player before it is thrown, the accelerometer will generate travel information assuming that it is already in mid-air, which pollutes the true distance measurement data.

It would also be desirable to detect the type of throw, whether the ball was caught or dropped, and the number of successive throws. Single player games may also be enhanced by an electronic ball that emits audible feedback relating to the throw.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided a throwable object comprising a body, the body housing: a throw sensor comprising at least one of an inertial measurement unit (IMU) and a barometric pressure sensor, the throw sensor arranged to periodically measure travel data describing the motion of the object during a throw, wherein the travel data relates to one or more of the object's position, speed, height, acceleration, velocity, angular rate, roll, pitch, or yaw; a processor arranged to receive travel data measurements from the throw sensor and to determine, during the throw, whether a recent travel data measurement is different to a previous travel data measurement; and a speaker arranged to emit a sound when the processor determines a difference.

It will be understood that such a throwable object provides for improved feedback to a user, for example when playing a throwing game with the object, because a sound is emitted when changes are detected in the object's motion during a throw. This means that the speaker may emit a sound when the object is moving through the air and reaches a certain height, or speed, or when the object is thrown in a certain way such that its motion, e.g. spin meets the aims of a game. The player can be rewarded by audible feedback during the throw, rather than waiting to catch the object and then looking to see what information, e.g. maximum height is displayed after the event. This makes throwing games more enjoyable. In throwing games that involve multiple players, the experience can be more intense as players hear feedback about each other's throws during the game. In applications other than a game, it may also be advantageous for a user of the throwable object to receive feedback about the throw while the object is still in the air. For example, if a user is throwing projectiles for a particular purpose (e.g. to hit a target) then early feedback during the throw can let the user know whether the throw is likely to be successful and another object can be launched more quickly than if the user has to wait for feedback after the first object has landed.

In a preferred set of embodiments the speaker is arranged to emit a sound when the processor determines a difference that exceeds or equals a predetermined threshold. Accordingly one or more predetermined thresholds that correspond to travel data of interest may be programmed into the processor. For example, the object reaching a certain height from the ground, or a certain speed, or a particular type of throw being achieved. Preferably, the processor is arranged to determine whether the throw is one or more of an air throw, arc throw, high spin throw, straight horizontal throw, overarm throw, an underarm throw, a side throw, a baseball throw, a running throw, a stationary throw, a spiral throw, a straight vertical throw or other type of throw by comparing the measured travel data to predetermined travel data point(s) that uniquely describe each of the different types of throw.

The speaker may be arranged to emit one or more different sounds corresponding to features of interest in the motion of the object during a throw. In some embodiments the sound emitted by the speaker is different to an earlier sound emitted by the speaker prior to the processor determining the difference.

It will be understood, that in embodiments, the body can further house (or comprise) a memory storing one or more, and preferably a plurality of, different digital sound files. These sound files can be accessed by the processor for output using the speaker. Each sound file may be associated with one or more different features of interest in the motion of the object during a throw and/or different types of throw (e.g. using a database structure stored in the memory), so that the processor can select the sound file corresponding to the determined feature of interest or type of throw, and output the sound corresponding to the selected sound file. In such an embodiment, sound files can be added or deleted from the memory, and/or the stored associated between a sound file and a feature of interest or type of throw can be changed (e.g. by a user on an app on their smartphone that is connected, e.g. wirelessly, to the throwable object. As will be appreciated, this allows new sounds to be output by the object over time, and allows different throwable objects to be uniquely configured by a user.

It is desirable for the sound emitted by the speaker to provide an indication of the current motion of the object during a throw. Accordingly it is preferable that the recent travel data measurement is a current travel data measurement from the IMU. This means that the feedback given to a user may be almost instantaneous. It is also desirable for the feedback to be updated on a regular basis, for example so that different sounds are emitted if there are changes in the motion of the object during a throw. For example, processor may be arranged to, based on the travel data, determine a phase of flight of the throwable object and may emit different sounds, each of the different sounds being assigned to one or more different phases of flight. Accordingly it is preferable that the previous travel data measurement is the most recent travel data measurement preceding the current travel data measurement.

It will be understood that when the processor determines a difference between a recent travel data measurement and a previous travel data measurement, the difference may comprise a change in (absolute or relative) magnitude for the travel data, or a change in time, for example a rate of change for the travel data, or a second or further derivative with respect to time. In addition, or alternatively, other differences may be used to trigger when the speaker emits a sound.

The inertial measurement unit (IMU) may be any electronic device that can measure the linear and/or angular acceleration experienced by the body when the object is in motion. In a preferred set of embodiments the IMU comprises an accelerometer, a gyroscope, and optionally a geomagnetic field sensor, arranged to measure one or more of the object's position, speed, height, acceleration, velocity, angular rate, roll, pitch, or yaw. The IMU may comprise up to three accelerometers and up to three gyroscopes. It will be understood that a geomagnetic field sensor or magnetometer is any device that can measure the Earth's magnetic field and hence assist in calibration against orientation drift. The processor may be arranged to process the travel data as necessary to calculate parameters such as position, speed, and/or height. For example, acceleration data can be integrated over time to provide the speed of the object and/or calculate a relative height change during the throw.

The barometric pressure sensor may be any electronic device that can measure atmospheric pressure. Such sensors are also known as pressure altimeters or altitude meters. In a preferred set of embodiments the barometric pressure sensor is arranged to measure the height of the object based on an atmospheric pressure measurement. Typically, such a sensor may allow for height measurements with an accuracy of ±10 cm. The Applicant has realised that a barometric pressure sensor provides benefits over an IMU for height measurement, because it can measure the height of the object relative to the ground during a throw. This avoids the need for manual input of a starting height for the object before the throw. It is also made easier for the processor to calculate a cumulative height for multiple throws. Preferably the barometric pressure sensor further comprises a temperature sensor, and is arranged to measure the height of the object based on an atmospheric pressure and temperature measurement. This improves the accuracy of the height measurement.

The throwable object may comprise one or more further sensors to assist in measuring travel data of interest. In a preferred set of embodiments the body further houses a capacitive proximity sensor arranged to measure a change in capacitance at the surface of the body. The Applicant has recognised that such a capacitive proximity sensor can provide measurements that advantageously enable the processor to detect the difference between the object being caught and hitting the ground (not caught). Such detection may be improved if the object is provided with a clearance between the capacitive proximity sensor and the location where the hands may hold the object, such as a non-metallic, or more generally, a non-conducting shell. A measurement of deceleration from the IMU does not distinguish between the different ways that the object reaches the end of a throw, i.e. caught or not caught. In a preferred set of embodiments the processor is arranged to determine that the object is in touch-contact, or has been thrown, based on the measured change in capacitance. In various embodiments the processor, optionally by using the travel data, may be arranged to determine that or distinguish whether the object is in-flight, is being thrown, is being caught, is hitting the ground, is being hand-held or has been resting on the ground. Such determination or distinction may be improved if the object is provided with a clearance between the capacitive proximity sensor and the location where the hands may hold the object, such as a non-metallic, or more generally, a non-conducting shell.

The processor may be arranged to record progression of a game. An example of such a game is a game in which the object is repetitively thrown by one of a predetermined number of users, typically two, to another one of the users and in which based on measurements by the proximity sensor and/or on the travel data the processor records an amount of catches before the object is being dropped.

The set of embodiments in which the processor is arranged to determine that the object is in touch-contact, or has been thrown, based on the measured change in capacitance is considered novel and inventive in its own right, and thus , according to a further aspect of the present invention, there is provided a throwable object comprising: a body housing a capacitive proximity sensor arranged to measure a change in capacitance at the surface of the body; and a processor arranged to determine that the object is in touch-contact, or has been thrown, based on the measured change in capacitance.

It will be appreciated that using a capacitance measurement to determine when the object is in touch-contact, or has been thrown, can vastly augment the assessment of travel data measured by any other sensor as it enables the processor to differentiate between motion of the object while it is being held and thrown, or motion of the object while it is being caught, as compared to motion during a throw. Using the capacitive proximity sensor enables the start and end points of the actual throw, when the object is flying through the air, to be accurately determined. What is meant by touch-contact is that the surface of the body has come into close enough contact with another electrically conductive surface so as to generate a recognisable change in capacitance. The electrically conductive surface may be part of a user's body or part of another object that catches the object, for example a net or goal comprising a conductive mesh. Such touch-contact is therefore distinguished from the object landing on the ground. What is meant by the object having been thrown is that the surface of the body has left contact with another electrically conductive surface, such as a user's hand, so as to generate a recognisable change in capacitance.

A capacitive proximity sensor is a capacitive touch sensor that can sense not only physical touch but also touch within a predetermined proximity range. In at least some embodiments the capacitive proximity sensor has a proximity range of at least 5 cm and preferably 10 cm or more. The capacitive proximity sensor may conveniently be located on a printed circuit board mounted inside the body and there is no need to arrange capacitive sensors on the surface of the body.

In a set of embodiments the processor is arranged to determine that the object is in touch-contact when the capacitive proximity sensor measures a change in capacitance that equals or exceeds or falls below a predetermined threshold. In a set of embodiments the processor is arranged to determine that the object is in touch-contact, or has been thrown, when the capacitive proximity sensor measures a change in capacitance that is inside a predetermined threshold range.

In a set of embodiments the processor is arranged to determine that the object is in touch-contact, or has been caught, when the capacitive proximity sensor measures a change in capacitance that equals or exceeds a predetermined threshold, or measures a change in capacitance that is inside a predetermined threshold range. Preferably the predetermined threshold or threshold range is set to indicate that the object is in touch-contact because it is being held by a user or it has been caught, or to indicate that the object has been thrown because the object is no longer being held by a user. Changes in capacitance may conveniently be used to assess the way in which the object is caught, for example in one hand or both hands.

Advantageously, the capacitance measurements can be used by the processor to decide when to take into account the travel data measurements received from the throw sensor. For example, it may be desirable for the processor to integrate the acceleration measured by the throw sensor only from the point in time that the object, e.g. ball leaves the hand. Detecting when the ball is being held and when it has left the hand can minimise the anomalies in accelerometer measurements and improve IMU accuracy. Thus in a preferred set of embodiments the processor is arranged to process the travel data measurements received from the throw sensor depending on when the object is determined to be in touch-contact and/or to have been thrown.

In a set of embodiments the throw sensor is also arranged to periodically measure travel data describing the motion of the object before and/or after the object has been thrown; and the processor is arranged to determine that the object is in touch-contact, and/or that the object has been thrown, further based on a travel data measurement, or a difference between a current travel data measurement and a previous travel data measurement. The travel data measurements from the throw sensor may also be used to assess the motion of the object before and/or after the object has been thrown.

It may be desirable that measurements from the capacitive proximity sensor are also used to provide an audible feedback. In a set of embodiments the speaker is arranged to emit a sound when the processor determines that the object is in touch-contact. It is further desirable for the processor to use the measurements from the capacitive proximity sensor to assist in analysing the motion of the object during a throw. In a preferred set of embodiments the processor is arranged to evaluate the travel data measurements from a time when the processor detects that the object has been thrown to a subsequent time when the processor detects that the object is in touch-contact so as to evaluate travel data describing the motion of the object during a throw. Preferably the processor is arranged to determine the distance between the position of the object at the time when the object was thrown and the position of the object at the time when the object was in touch-contact based on the travel data measurements.

In addition, or alternatively, the processor is preferably arranged to determine the maximum height of the object between the time when the object was thrown to the time when the object was in touch-contact based on the travel data measurements. Preferably the maximum height is relative to the height of the object at the time when the object was thrown.

In addition, or alternatively, the processor is preferably arranged to count the number of full rolls or partial rolls the object makes during the throw based on the travel data measurements.

The speaker may be housed in the body in any suitable arrangement as long as the sounds emitted by the speaker are audible to a user of the throwable object. However the Applicant has appreciated that it can be beneficial to arrange the speaker such that its impact on throwability of the object is minimised. In a set of embodiments the body comprises a major axis, and the speaker has a centre of mass that is substantially centred on the major axis. This means that the speaker does not alter the normal centre of mass of the object.

The Applicant has further recognised that the position of the speaker can affect how sound is emitted from the body and its audibility during use. In embodiments where the object has a shape dictating the direction in which it is normally thrown, for example a vortex football, then it is desirable for any sound emitted by the speaker to be directed towards the thrower. Thus in a preferred set of embodiments the body has a front end that faces forward when the object is thrown in a forward direction, wherein the front end is shaped to provide the least amount of air resistance against a forward motion of the object when the object is thrown with the front end facing in the forward direction, and the speaker is arranged to face away from the front end so as to direct sound in a backward direction that is substantially opposite to the forward direction.

This is considered novel and inventive in its own right, and thus, according to a further aspect of the present invention, there is provided a throwable object comprising: a body having a front end that faces forward when the object is thrown in a forward direction, wherein the front end is shaped to provide the least amount of air resistance against the forward motion of the object when the object is thrown with the front end facing in the forward direction; and a speaker facing away from the front end so as to direct sound in a backward direction that is substantially opposite to the forward direction.

A speaker directed in the opposite direction of travel, e.g. at the back end of the object, has the following advantages:

-   -   sound is directed to the throwing person, making sound most         audible for the thrower;     -   when the shuttle is being caught at the front end, the catcher's         hands don't block the main speaker outlet at the back end;     -   the speaker facing away from the front end prevents wind (air         pressure) from pressing against the speaker membrane during a         throw; since wind pressing against a speaker membrane gives the         undesired effect of lowering the volume.

Preferably the body further comprises a back end opposing the front end, and the speaker is located within the back end, or adjacent to the back end. In a set of embodiments the front end substantially curves towards the back end, and the back end is substantially planar. Preferably the back end comprises a substantially planer face arranged to intersect the major axis. The speaker may be arranged to form the back end of the body by extending in a plane that is substantially perpendicular to the major axis.

In a preferred set of embodiments the front end has a three-dimensional shape substantially corresponding to a throwable ball such as a football or rugby ball. The throwable object may take the form of a shuttle, ball, football, projectile, torpedo, or vortex football.

In a set of embodiments the body further houses a battery arranged to power the speaker, and a charging port, wherein the charging port is connected to the battery and located within the back end. Preferably the speaker comprises a speaker cavity housing one or more of the battery, the capacitive proximity sensor, the IMU, or the barometric pressure sensor. This provides for a particularly compact arrangement of components inside the body.

In a set of embodiments the speaker cavity is a waterproof casing, or is defined by an internal chamber within the body.

In a set of embodiments the speaker cavity comprises a passive speaker membrane.

In a set of embodiments the speaker cavity extends into the body, towards the front end.

In a set of embodiments the throwable object further comprises a fastener located at the back end of the body, wherein the fastener is arranged to removably connect the body to a tail. Such a tail may be used to change the aerodynamic properties of the body. Preferably the fastener is chosen from: a push-fit fastener, a bayonet fastener, or a screw-fit fastener. Such fasteners advantageously enable different tails to be removably connected to the body. Preferably the tail is one of a group of different tails, and the fastener is arranged to removably connect the body to any one of the group of different tails. This is considered novel and inventive in its own right, and thus according to a further aspect of the present invention there is provided a kit comprising a body and multiple different tail portions that can be interchangeably connected to the body to form multiple different throwable objects.

In a set of embodiments the tail has a major axis that is collinear with a, or the, major axis of the body. In embodiments where the speaker is arranged centrally in the body and the axes are collinear, the speaker is prevented from rotating too much around its body, and thus minimizes the Doppler effect during a throw.

In a set of embodiments the tail comprises a capping portion that is shaped to substantially cap the back end. Preferably the capping portion comprises one or more apertures for the passage of sound waves from the speaker. Advantageously the tail covers the speaker to make it shock proof while the aperture(s) act to port out the sound.

There will now be described some general features of the throwable object that may be provided according to embodiments of any of the foregoing aspects of the invention.

In a set of embodiments the object further comprises lift-generating fins extending radially from the body. In addition, or alternatively, the object further comprises lift-generating fins extending radially from the tail. In some embodiments the tail comprises an elongate rod that is centred about, and extends along, the major axis of the tail; and the lift-generating fins extend radially from the elongate rod. Additionally, or alternatively, in some embodiments the tail comprises a handle.

In a set of embodiments the object further comprises a resilient outer body arranged to at least partially encase the body. Preferably the resilient outer body comprises a shock absorbent foam.

In a set of embodiments the body further houses a transceiver arranged to transmit travel data and/or information relating to any of the determinations made by the processor. Preferably the transceiver is arranged to wirelessly transmit the travel data and/or information relating to any of the determinations made by the processor using a short-range wireless communications protocol, such as Bluetooth™ Low Energy.

In a set of embodiments the body further houses a display arranged to display information relating to the travel data and/or information relating to any of the determinations made by the processor.

It should be understood that any of the features described above in relation to a particular set of embodiments may be combined with the features of another set of embodiments without any limitations other than those imparted by the broadest aspects of the invention as defined hereinabove.

BRIEF DESCRIPTION OF THE DRAWINGS

Some illustrative embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is an exploded view of a shuttle in accordance with an embodiment of the present invention;

FIG. 2 is another exploded view of the shuttle of FIG. 1;

FIG. 3 is a cross-sectional view illustrating the internal structure of the shuttle of FIG. 1;

FIG. 4 is a block diagram illustrating the components of the electronics of the shuttle of FIG. 1,

FIG. 5 illustrates different types of trajectories that the shuttle may follow according to the type of throw;

FIG. 6 is a representation of the trajectory of the shuttle when it is thrown;

FIG. 7 illustrates a second type of tail portion that may be connected with the body of the shuttle of FIG. 1; and

FIG. 8 illustrates a third type of tail portion that may be connected with the body of the shuttle of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 3 show a shuttle 10 which a user may pick up and throw. The shuttle 10 has a head 12 that is removably connected to a tail 40. The connection is such that the major axis 11 of the head 12 is collinear with the major axis of the tail 40.

The head 12 has a front end 20 and a back end 22. The front end 20 is shaped to provide the least amount of drag against the forward movement of the shuttle 10 when the front end 20 faces the forward direction 100. The back end 22 is substantially planer in a plane that is orthogonal to the major axis 11 of the head 12.

The head also comprises: a speaker 16, a speaker cavity 27, a bass radiator 26, an electronic circuit board 23, a battery 24, a power button 18 for turning the electronics on/off, a dot matrix display 25, a push-fit fastener 37, and a charging port for (re)charging the battery 24.

The push-fit fastener 37 defines a circular lip 38 surrounding a circular aperture 13 at the back end 22. The circular aperture 13 and the circular lip 38 are centred about the major axis 11 of the head 12. The circular lip 38 is arranged to compressively slot into a mating aperture 47 defined in the tail 40. However, as will be described below, the push-fit fastener 37 enables the head 12 to interchangeably connect with a plurality of different tails. Examples of some different types of tails 70, 80 are illustrated in FIGS. 7 and 8.

The speaker 16 is mounted within the circular aperture 13 and arranged to emit sound in a backward direction 200, which is opposite to the forward direction. It will be appreciated that the speaker 16 is also centred about the major axis 11 of the head 12. This ensures that the weight of the speaker 16 is evenly distributed when the head 12 spins about the major axis 11.

The speaker 16 comprises a speaker cavity 27 that is arranged within the head 12. Housed within the speaker cavity are the battery 24, the electronic circuit board 23, and the dot matrix display 25. Preferably, the speaker cavity 27 is sealed to ensure that it is water tight. Further, a washer may be used to sealably mount the speaker 16 to the circular aperture 13 at the back end 22 of the head 12.

The battery 24 is positioned at the front end of the speaker cavity, i.e. the end that faces the forward direction when the shuttle 10 is thrown. This ensures that the weight of the battery 24 is near the front end 20 of the shuttle when it is thrown, which is beneficial as it allows the shuttle 10 to be thrown over larger distances.

The charging port 52 is positioned at the back end 22 of the head 12, adjacent to the speaker 16. This ensures that the charging port 52 is covered by the tail 40 when the tail is connected to the head 12.

At the right wall of the speaker cavity 27 (as seen from FIG. 3) is a passive diaphragm 26 arranged to oscillate at lower frequencies than the speaker 16. Preferably, the passive diaphragm provides a bass sound.

The dot matrix display 25 is mounted at the left side of the speaker cavity 27 and is visible from the outside of the shuttle through a display aperture in the head 12.

Surrounding the speaker cavity 27 is a layer of shock absorbent foam 29 that is shaped so that the front end 22 takes the form of the front end of a rugby ball. To provide grip, the layer of shock absorbent foam 29 is covered by a layer of rubber skin.

The tail 40 comprises a cap portion 42, an elongate rod 46, and three lift-generating fins (i.e. fins that generate aerodynamic lift).

The cap portion 42 comprises a front end 49 that is substantially planar and shaped to cap the back end 22 of the head 12. The front end 49 of the tail 40 rests flat against the back end 22 of the head 12, when the tail 40 is fastened to the head 12 with the push-fit fastener 37. Thus it will be appreciated that the tail 40 covers the speaker 16 and the charging port 52 when the tail 40 is connected to head 12.

The cap portion 42 is shaped to define a concave portion 50 that extends from the front end 49 of the tail 40 and curves towards the major axis 41 of the tail 40 so as to meet with the elongate rod 46. The elongate rod 46 is centred about the major axis 41 of the tail 40 and axially extends from the back end 51 of the capping portion 42.

The cap portion 42 also comprises a plurality of apertures 44 to enable sound emitted by the speaker 16 to pass through.

Extending from the elongate rod 46 are the three lift-generating fins 48. The lift-generating fins 48 are radially arranged about the major axis 41 of the tail 40, and equally spaced apart. The lift-generating fins 48 provide lift to allow the shuttle 10 to be thrown over a longer distance.

FIG. 4 provides a more detailed block diagram of the electronic circuit board 23 shown in FIG. 1. The electronic circuit board 23 comprises: a throw sensor 37; a barometric pressure sensor (i.e.

a pressure altimeter) 33; a processor 35 (e.g. an ARM™ Cortex M-series); and a transceiver 36. These components are interconnected using suitable lines and/or buses (not shown).

The throw sensor 37 comprises an inertial measurement unit (IMU) 31 and a capacitive proximity sensor 32. It periodically measures travel data describing the motion of the shuttle 10 before, during, and after a throw. The travel data includes the acceleration, velocity, speed, position, height, angular rate, roll, pitch, and yaw of the shuttle 10.

The IMU 31 is a standard IMU (such as a XSens™ MTi series IMU) that uses accelerometers, gyroscopes and, optionally, a geomagnetic field sensor (i.e. a magnetometer) to measure travel data comprising the acceleration, velocity, speed, position, angular rate, roll, pitch, and yaw of the shuttle 10. The IMU 31 also measures the relative change in height of the shuttle 10 based on relative changes in the shuttle's velocity and position.

The barometric pressure sensor 33 (e.g. a Parallax Inc. 29124) comprises a temperature sensor 34, and measures the atmospheric pressure and temperature to determine the altitude of the shuttle 10. The barometric pressure sensor 33 works on the known principle that the pressure within a column of air varies in a known way with height. The mathematical relationship that relates height to atmospheric pressure and height is:

z=(RT/gM)·log e(p _(o) /p)

where z is the height difference between the starting height and the current height, R is the gas constant, T is temperature of the air measured in Kelvin, g is the acceleration due to gravity, M is the molar mass of the gas (in this case air), p_(o) is the measured atmospheric pressure at the starting height and p is the measured atmospheric pressure at the current height.

The capacitive sensor 32 periodically measures the change in capacitance at the surface 30. The capacitive sensor 32 is a capacitive proximity sensor, such as Texas Instruments™ MSP430 MCU, which may have a range of 10 cm or more. This means that the capacitive sensor 32 can be placed on the same electronic circuit board 23 as the processor 35 and other sensors inside the body of the shuttle 10. The capacitive proximity sensor 32 can detect a human touch through the speaker cavity 27 and layer of shock absorbent foam 29.

A change in capacitance generally occurs when the surface 30 is in contact with a conductive surface, such as a human hand 62, wearable metallic clothing, or metallic basketball net. As will be described in more detail below, the processor 35 uses the measurements from the capacitive sensor 32 to determine when the shuttle 10 is in touch-contact based on the measured change in capacitance.

The transceiver 36 is a standard radio transceiver that communicates with a peripheral device such as the smartphone or remote display unit. Preferably, the transceiver 36 communicates using a short-range wireless communications protocol such as Bluetooth® Low Energy, or ultra-wideband radio communications protocol. However, the transceiver 36 may communicate using other types of communication protocols. As will be described further below, the processor 35 instructs the transceiver 36 to send travel data to the user's smartphone for displaying the travel data to the user.

In use, the processor 35 receives the measurements from the capacitive proximity sensor 32, the IMU 31, and the barometric pressure sensor 33. The measurements from the capacitive proximity sensor 32 are used to determine when the shuttle is in touch-contact by determining whether or not a measured change in capacitance exceeds a predetermined threshold. The predetermined threshold indicates that the shuttle 10 is being held in a hand 62 of the user (see FIG. 6). If the measured change in capacitance exceeds the predetermined threshold, the processor 35 determines that the shuttle 10 is in touch-contact. In this state, the shuttle 10 is not being thrown.

It will be appreciated that the measured change in capacitance may vary, depending on whether the shuttle 10 is being held by a user, caught by a user, held by a conductive holder, or caught by a conductive holder (e.g. a metallic basketball net). For example, the change in capacitance may be different when a user holds the shuttle with one hand as compared to when the user catches the shuttle 10 with both hands. Accordingly, the processor 35 may, in some embodiments, apply one or more different predetermined thresholds tests to determine when the shuttle 10 is being held and when the shuttle 10 has been caught. The processor 35 may also determine whether the shuttle is being held by a user or a conductive holder.

It will be appreciated that when the shuttle impacts the ground (i.e. a non-conductive surface), it may not measure a change in capacitance, or it may measure a change in capacitance that does not exceed the predetermined threshold. In this way, the capacitive proximity sensor 32 enables the shuttle 10 to distinguish between when the shuttle 1 is held or caught, and when the shuttle 10 hits the ground. Additionally or alternatively, to further improve the determination of when the shuttle 10 has been caught, the processor 10 may determine whether the measured travel data describing the motion of shuttle 10 matches a predetermined travel data point, or a set of predetermined travel data points, that describe a typical motion of the shuttle 10 when it is, or is being, caught. For example, the predetermined travel data points may comprise a predetermined travel data point describing a typical position/orientation which the shuttle 10 may have when it is caught, and/or a set of predetermined travel data points that describe a typical trajectory which the shuttle 10 may follow whilst it is being caught. Preferably, the predetermined travel data points relate to one or more of the acceleration, velocity, speed, position, height, angular rate, roll, pitch, and yaw of the shuttle 10.

The measurements from the capacitive proximity sensor 32 are also used by the processor 35 to determine when the shuttle has been thrown. This is done by determining whether or not the change in capacitance on the surface of the shuttle 10 is below a predetermined threshold. For example, when the change in capacitance is below a predetermined threshold indicative of when the shuttle is being held and/or caught, the processor may determine that the shuttle 10 has been thrown.

Additionally or alternatively, to further improve the determination of when the shuttle 10 has been thrown, the processor 10 may determine whether the measured travel data describing the motion of shuttle 10 matches a predetermined travel data point, or a set of predetermined travel data points, that describe a typical motion of the shuttle 10 when it is, or is being, thrown. For example, the predetermined travel data points may comprise a predetermined travel data point describing a typical position/orientation which the shuttle 10 may have when it is thrown, and/or a set of predetermined travel data points that describe a typical trajectory which the shuttle 10 may follow whilst it is being thrown. Preferably, the predetermined travel data points relate to one or more of the acceleration, velocity, speed, position, height, angular rate, roll, pitch, and yaw of the shuttle 10.

Further optionally, the processor 35 may determine the type of throw based on the measured travel data. For example, the processor 35 may analyse the measured travel data leading up to a throw, and match the analysed data to a predetermined travel data point, or a set of predetermined travel data points, that describe the typical trajectory of a shuttle 10 during a particular type of throw (e.g. an overarm throw). If a match is found, the processor 35 determines that the shuttle 10 has been thrown using a throw described by the predetermined travel data points (e.g. an overarm throw).

FIG. 5 illustrates examples of the types of throw that may be determined. Preferably, the processor determines whether the throw is one or more of an air throw, arc throw, high spin throw, straight throw, overarm throw, an underarm throw, a side throw, a baseball throw, a running throw, a stationary throw, or other type of throw by comparing the measured travel data to predetermined travel data point(s) that uniquely describe each of the different types of throw.

Additionally or alternatively, the processor may determine the type of throw by comparing the measured travel data during a throw to predetermined travel data points that describe the type of throw during a throw.

Returning to the present embodiment, the processor 35 also analyses the travel data during the throw (i.e. between the time when the processor 35 determines that the shuttle 10 has been thrown and the time when the processor 35 next determines that the shuttle 10 is in touch-contact) to determine information and statistics about the throw.

Specifically, the processor 35 periodically analyses the current travel data from the throw sensor 37 to determine the current height, speed, position, number of rolls, angular rate (i.e. spin speed), pitch, yaw, velocity, and acceleration of the shuttle 10. The processor 35 also determines how the magnitude of the current travel data changes relative to previously measured travel data at an earlier time during the throw (e.g. the initial travel data at the start of the throw). When there is a difference between the magnitude of the current travel data and the magnitude of the earlier travel data, the processor 35 instructs the speaker 16 to output a sound. Preferably, the difference may be compared to a predefined threshold, and the processor 35 may only instruct the speaker 16 to output a sound when the difference exceeds the threshold. Further preferably, the processor may instruct the speaker 16 to output a first sound when it measures a first difference exceeding a first threshold. Subsequently, the processor may instruct the speaker 16 to output a second sound when it next measures a difference exceeding a second threshold.

The processor 35 is also arranged to analyse the travel data during the throw to determine the distance the shuttle 10 is thrown, the maximum altitude of the shuttle 10 (optionally relative to the starting altitude at the time when the shuttle 10 was thrown), the number of rolls the shuttle made, and the maximum speed and acceleration of the shuttle 10. The processor 35 also determines the number of successive throws and catches based on the number of successive throw and catch determinations. This enables the processor 35 to accumulate the information and statistics that it determined about each successive throw, and thereby provide aggregated information and statistics over a series of successive throws. It will be appreciated that the processor 35 determines when the cycle of successive throws ends by determining that the shuttle 10 has not been caught after a throw (e.g. by determining that, after determining that a throw has occurred, the shuttle 10 has come to a rest without a touch-contact determination).

It will be appreciated that since the processor 35 is able to determine when the shuttle 10 has been thrown and caught, it is more accurately able to determine the time during a throw, and thereby provide more accurate information about the throw. For example, by determining when a user throws the shuttle 10 (e.g. the moment when a user releases the shuttle 10 after moving it to throw it), the pre-throw movement of the shuttle 10 is not considered by the processor 35 to be part of the total distance travelled.

FIG. 6 illustrates an example wherein the processor 35 instructs the speaker 16 to output a sound depending on the measured altitude of the shuttle 10.

Initially, when the user throws the shuttle 10 with his hand 62, the processor 35 determines that the shuttle 10 has been thrown based on the measurements from the capacitive proximity sensor 32. At this point, the processor 35 records the initial altitude of the shuttle 10 at the start of the throw. The altitude measurement is provided by the barometric pressure sensor 33.

During the throw, the processor 35 periodically monitors the altitude measurements and determines when the shuttle 10 reaches certain altitudes relative to the initial altitude of the shuttle 10. The relative altitude provides a measure of how high the shuttle is being thrown. In this example, the processor 10 is set to determine when the shuttle 10 reaches a height of 2 meters, 3 meters, 4 meters, and 10 meters. Whenever, the shuttle reaches one of these specified heights, the speaker 16 emits a sound. The emitted sound is different for each height—specifically, the speaker emits a “ding”, “bong”, “woop”, and “daang” sound for a respective height of 2 meters, 3 meters, 4 meters, and 10 meters.

Of course, it will be appreciated that the processor 35 may periodically monitors one or more other travel data measurements from the throw-sensor 37, and the speaker may emit a different sound whenever a given relative change in the travel data measurement is reached.

FIG. 7 illustrates an alternative tail 70 which the head 12 of the above-mentioned embodiments may interchangeably connect with. Tail 70 comprises a capping portion that is shaped to cap the back end of 22 of the head 12, and shaped to match the shape of the front end 20 of the head 12. In this way, the shuttle 700 is shaped to form a rugby ball.

FIG. 8 illustrates another alternative tail 80 which the head 12 of the above-mentioned embodiments may interchangeably connect with. Tail 80 is the same as tail 40 of FIG. 1, expect that instead of lift-generating fins 48 extending form the elongate portion 46, the elongate portion of tail 80 has a handle 82 extending therefrom.

While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. For example, different features or embodiments can be combined with other features or embodiments described herein. The descriptions above are intended to be illustrative, not limiting. Thus it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims and clauses set out below.

Clauses:

-   1. A throwable object comprising:

a body housing a capacitive proximity sensor arranged to measure a change in capacitance at the surface of the body; and

a processor arranged to determine that the object is in touch-contact, or has been thrown, based on the measured change in capacitance.

-   2. A throwable object according to clause 1, wherein the processor     is arranged to determine that the object is in touch-contact, or has     been caught, when the capacitive proximity sensor measures a change     in capacitance that equals or exceeds or falls below a predetermined     threshold, or measures a change in capacitance that is inside a     predetermined threshold range. -   3. A throwable object according to clause 2, wherein the     predetermined threshold or threshold range is set to indicate that     the object is in touch-contact because it is being held by a user or     it has been caught, or to indicate that the object has been thrown     because the object is no longer being held by a user. -   4. A throwable object according to any preceding clause, the body     further housing a speaker and the speaker being arranged to emit a     sound when the processor determines that the object is in     touch-contact. -   5. A throwable object according to any preceding clause, the body     further housing an inertial measurement unit (IMU), arranged to     periodically measure travel data describing the motion of the     object, wherein the processor is arranged to process the travel data     depending on when the object is determined to be in touch-contact     and/or to have been thrown. -   6. A throwable object according to any preceding clause, further     comprising a throw sensor comprising at least one of an inertial     measurement unit (IMU) and a barometric pressure sensor, the throw     sensor arranged to periodically measure travel data describing the     motion of the object, wherein:

the travel data relates to one or more of the object's position, speed, height, acceleration, velocity, angular rate, roll, pitch, or yaw; and

the processor is arranged to receive a travel data measurement from the throw sensor and determine that the object is in touch-contact, and/or that the object has been thrown, further based on a travel data measurement, or a difference between a current travel data measurement and a previous travel data measurement.

-   7. A throwable object according to clause 6, wherein the processor     is arranged to evaluate the travel data measurements from a time     when the processor detects that the object has been thrown to a     subsequent time when the processor detects that the object is in     touch-contact so as to evaluate travel data describing the motion of     the object during a throw. -   8. A throwable object according to clause 7, wherein the processor     is arranged to determine a distance between a position of the object     at a time when the object was thrown and a position of the object at     a time when the object was in touch-contact based on the travel data     measurements. -   9. A throwable object according to clause 7 or 8, wherein the     processor is arranged to determine a maximum height of the object     between a time when the object was thrown to a time when the object     was in touch-contact based on the travel data measurements. -   10. A throwable object according to clause 9, wherein the maximum     height is relative to a height of the object at the time when the     object was thrown. -   11. A throwable object according to any of clauses 7 to 10, wherein     the processor is arranged to count the number of full rolls or     partial rolls the object makes during the throw based on the travel     data measurements. -   12. A throwable object according to any preceding clause, wherein     the body has a front end that faces forward when the object is     thrown in a forward direction, wherein the front end is shaped to     provide the least amount of air resistance against a forward motion     of the object when the object is thrown with the front end facing in     the forward direction, the throwable object further comprising a     speaker facing away from the front end so as to direct sound in a     backward direction that is substantially opposite to the forward     direction. -   13. A throwable object according to clause 12, wherein the speaker     is arranged to emit a sound when the processor determines that the     object is in touch-contact. -   14. A throwable object according to clause 12 or 13, when dependent     on any of clauses 4 to 8, wherein:

the processor is arranged, during the throw, to determine whether a recent travel data measurement is different to a previous travel data measurement; and

the speaker is arranged to emit a sound when the processor determines a difference.

-   15. A throwable object according to clause 14, wherein the speaker     is arranged to emit a sound when the processor determines a     difference that exceeds or equals a predetermined threshold. -   16. A throwable object according to clause 14 or 15, wherein sound     emitted by the speaker is different to an earlier sound emitted by     the speaker prior to the processor determining the difference. -   17. A throwable object according to any of clauses 14 to 16, wherein     the recent travel data measurement is the current travel data     measurement from the IMU. -   18. A throwable object according to clause 17, wherein the previous     travel data measurement is the most recent travel data measurement     preceding the current travel data measurement. -   19. A throwable object according to any of clauses 3 to 18, wherein     the IMU comprises an accelerometer, a gyroscope, and optionally a     geomagnetic field sensor, arranged to provide travel data relating     to one or more of the object's position, speed, height,     accelerometer, velocity, angular rate, roll, pitch, or yaw. -   20. A throwable object according to any of clauses 6 to 19, wherein     the barometric pressure sensor is arranged to measure the height of     the object based on an atmospheric pressure measurement. -   21. A throwable object according to any of clauses 6 to 20, wherein     the barometric pressure sensor comprises a temperature sensor, and     is arranged to measure the height of the object based on an     atmospheric pressure and temperature measurement. -   22. A throwable object according to any of clauses 12 to 21, wherein     the body further comprises a major axis, and the speaker has a     centre of mass that is substantially centred on the major axis. -   23. A throwable object according to any of clauses 12 to 22, wherein     the body further comprises a back end opposing the front end, and     the speaker is located within the back end, or adjacent to the back     end. -   24. A throwable object according to clause 23, wherein the front end     substantially curves towards the back end, and the back end is     substantially planar. -   25. A throwable object according to clause 23 or 24, wherein the     body further comprises a battery arranged to power the speaker, and     a charging port, wherein the charging port is connected to the     battery and located within the back end. -   26. A throwable object according to clause 25, wherein the speaker     comprises a speaker cavity housing one or more of the battery, the     capacitive proximity sensor, or the throw sensor. -   27. A throwable object according to clause 26, wherein the speaker     cavity is a waterproof casing, or is defined by an internal chamber     within the body. -   28. A throwable object according to clause 26 or 27, wherein the     speaker cavity comprises a passive speaker membrane. -   29. A throwable object according to any of clauses 23 to 28, wherein     the speaker cavity extends into the body, towards the front end. -   30. A throwable object according to clause 23 to 29, further     comprising a fastener located at the back end of the body, wherein     the fastener is arranged to removably connect the body to a tail. -   31. A throwable object according to clause 30, wherein the fastener     is one of the group comprising a push-fit fastener, a bayonet     fastener, or a screw-fit fastener. -   32. A throwable object according to clause 30 or 31, wherein the     tail is one of a group of different tails, and the fastener may     removably connect the body to any one of the group of different     tails. -   33. A throwable object according to any of clauses 30 to 32, wherein     the tail has a major axis that is collinear with a, or the, major     axis of the body. -   34. A throwable object according to any of clauses 30 to 33, wherein     the tail comprises a capping portion that is shaped to substantially     cap the back end. -   35. A throwable object according to clause 34, wherein the capping     portion comprises one or more apertures for the passage of sound     waves emitted by the speaker. -   36. A throwable object according to any preceding clause, further     comprising lift-generating fins extending radially from the body. -   37. A throwable object according to any of clauses 30 to 35 further     comprising lift-generating fins extending radially from the tail. -   38. A throwable object according to clause 37, when dependent on     clause 33, wherein:

the tail comprises an elongate rod that is centred about, and extends along, the major axis of the tail; and

the lift-generating fins extend radially from the elongate rod.

-   39. A throwable object according to any of clauses 30 to 38, wherein     the tail comprises a handle. -   40. A throwable object according to any preceding clause, further     comprising a resilient outer body arranged to at least partially     encase the body. -   41. A throwable object according to clause 40, wherein the resilient     outer body comprises a shock absorbent foam. -   42. A throwable object according to any of clauses 5 to 41, the body     further housing a transceiver arranged to transmit travel data     and/or information relating to any of the determinations made by the     processor. -   43. A throwable object according to clause 42, wherein the     transceiver is arranged to wirelessly transmit the travel data     and/or information relating to any of the determinations made by the     processor using a short-range wireless communications protocol. -   44. A throwable object according to any of clauses 5 to 43, the body     further housing a display arranged to display information relating     to the travel data and/or information relating to any of the     determinations made by the processor. -   45. A throwable object comprising:

a body having a front end that faces forward when the object is thrown in a forward direction, wherein the front end is shaped to provide the least amount of air resistance against the forward motion of the object when the object is thrown with the front end facing in the forward direction; and

a speaker facing away from the front end so as to direct sound in a backward direction that is substantially opposite to the forward direction.

-   46. A throwable object according to clause 45, wherein the body     further comprises a major axis, and the speaker has a centre of mass     that is substantially centred on the major axis. -   47. A throwable object according to clause 45 or 46, wherein the     body further comprises a back end opposing the front end, and the     speaker is located within the back end, or adjacent to the back end. -   48. A throwable object according to clause 47, wherein the front end     substantially curves towards the back end, and the back end is     substantially planar. -   49. A throwable object according to clause 47 or 48, wherein the     back end comprises a substantially planer face arranged to intersect     the major axis. -   50. A throwable object according to any of clauses 45 to 49, wherein     the front end has a three-dimensional shape substantially     corresponding to a throwable ball such as a football or rugby ball. -   51. A throwable object according to clause 7 or 50, wherein the body     further comprises a battery arranged to power the speaker, and a     charging port, wherein the charging port is connected to the battery     and located within the back end. -   52. A throwable object according to clause 51, wherein the speaker     comprises a speaker cavity housing the battery. -   53. A throwable object according to clause 52, wherein the speaker     cavity is a waterproof casing, or is defined by an internal chamber     within the body. -   54. A throwable object according to clause 52, wherein the speaker     cavity comprises a passive speaker membrane. -   55. A throwable object according to any of clauses 52 to 54, wherein     the speaker cavity extends into the body, towards the front end. -   56. A throwable object according to clause 47 to 55, further     comprising a fastener located at the back end of the body, wherein     the fastener is arranged to removably connect the body to a tail. -   57. A throwable object according to clause 56, wherein the fastener     is one of the group comprising a push-fit fastener, a bayonet     fastener, or a screw-fit fastener. -   58. A throwable object according to clause 56 or 57, wherein the     tail is one of a group of different tails, and the fastener may     removably connect the body to any one of the group of different     tails. -   59. A throwable object according to any of clauses 56 to 58, wherein     the tail has a major axis that is collinear with a, or the, major     axis of the body. -   60. A throwable object according to any of clauses 56 to 59, wherein     the tail comprises a capping portion that is shaped to substantially     cap the back end. -   61. A throwable object according to clause 60, wherein the capping     portion comprises one or more apertures for the passage of sound     waves from the speaker. -   62. A throwable object according to any of clauses 45 to 61 further     comprising lift-generating fins extending radially from the body. -   63. A throwable object according to any of clauses 56 to 61 further     comprising lift-generating fins extending radially from the tail. -   64. A throwable object according to clause 63, when dependent on     clause 59, wherein:

the tail has an elongate rod that is centred about, and extends along, the major axis of the tail;

and the lift-generating fins extend radially from the elongate rod.

-   65. A throwable object according to any of clauses 59 to 64, wherein     the tail comprises a handle. -   66. A throwable object according to any preceding clause, further     comprising a resilient outer body arranged to at least partially     encase the body. -   67. A throwable object according to clause 66, wherein the resilient     outer body comprises a shock absorbent foam. -   68. A throwable object according to any of clauses 45 to 67, wherein     the throwable object takes the form of a shuttle, ball, football,     projectile, torpedo, or vortex football. -   69. A kit comprising a body and multiple different tail portions     that can be interchangeably connected to the body to form multiple     different throwable objects. -   70. A kit according to clause 69, wherein:

the body has a front end that faces forward when the object is thrown in a forward direction, the front end being shaped to provide the least amount of air resistance against the forward motion of the object when the object is thrown with the front end facing in the forward direction; and

a speaker facing away from the front end so as to direct sound in a backward direction that is substantially opposite to the forward direction.

-   71. A kit according to clause 69 or 70, wherein the body further     comprises a major axis, and the speaker has a centre of mass that is     substantially centred on the major axis. -   72. A kit according to any of clauses 69 to 71, wherein the body     further comprises a back end opposing the front end, and the speaker     is located within the back end, or adjacent to the back end. -   73. A kit according to clause 72, wherein the front end     substantially curves towards the back end, and the back end is     substantially planar. -   74. A kit according to clause 72 or 73, wherein the back end     comprises a substantially planer face arranged to intersect the     major axis. -   75. A kit according to any of clauses 69 to 74, wherein the front     end has a three-dimensional shape substantially corresponding to a     throwable ball such as a football or rugby ball. -   76. A kit according to clause 72 or 75, wherein the body further     comprises a battery arranged to power the speaker, and a charging     port, wherein the charging port is connected to the battery and     located within the back end. -   77. A kit according to clause 76, wherein the speaker comprises a     speaker cavity housing the battery. -   78. A kit according to clause 77, wherein the speaker cavity is a     waterproof casing, or is defined by an internal chamber within the     body. -   79. A kit according to clause 78, wherein the speaker cavity     comprises a passive speaker membrane. -   80. A kit according to any of clauses 77 to 79, wherein the speaker     cavity extends into the body, towards the front end. -   81. A kit according to clause 72 to 80, further comprising a     fastener located at the back end of the body, wherein the fastener     is arranged to removably and separately connect the body to each of     the multiple different tail portions. -   82. A kit according to clause 81, wherein the fastener is one of the     group comprising a push-fit fastener, a bayonet fastener, or a     screw-fit fastener. -   83. A kit according to any of clauses 81 to 82, wherein one or more     of the tail portions comprise a major axis that is collinear with     the major axis of the body, when connected together. -   84. A kit according to clause 83, wherein one or more of the tail     portions comprises a capping portion that is shaped to substantially     cap the back end. -   85. A kit according to clause 84, wherein the capping portion     comprises one or more apertures for the passage of sound waves from     the speaker. -   86. A kit according to any of clauses 69 to 85, further comprising     lift-generating fins extending radially from the body. -   87. A kit according to any of clauses 83 to 86, wherein one or more     of the tail portions further comprises lift-generating fins     extending radially from the tail portion. -   88. A kit according to clause 87, wherein:

the tail portion has an elongate rod that is centred about, and extends along, the major axis of the tail portion; and

the lift-generating fins extend radially from the elongate rod.

-   89. A kit according to any of clauses 83 to 88, wherein one or more     of the tail portions comprises a handle. -   90. A kit according to any of clauses 69 to 89, the body further     comprising a resilient outer body arranged to at least partially     encase the body. -   91. A kit according to clause 90, wherein the resilient outer body     comprises a shock absorbent foam. -   92. A kit according to any of clauses 69 to 91, wherein the body     houses:

a capacitive proximity sensor arranged to measure a change in capacitance at the surface of the body; and

a processor arranged to determine that the object is in touch-contact, or has been thrown, based on the measured change in capacitance.

-   93. A kit according to any of clauses 69 to 91, wherein the body     houses a throw sensor comprising at least one of an inertial     measurement unit (IMU) and a barometric pressure sensor, the throw     sensor arranged to periodically measure travel data describing the     motion of the object. -   94. A kit according to clause 93, wherein the IMU comprises an     accelerometer, a gyroscope, and optionally a geomagnetic sensor,     arranged to provide travel data relating to one or more of the     object's position, speed, height, acceleration, velocity, angular     rate, roll, pitch, or yaw. -   95. A kit according to any of clauses 93 to 94, wherein the     barometric pressure sensor is arranged to measure the height of the     object based on an atmospheric pressure measurement. 

1. A throwable object comprising: a body housing a capacitive proximity sensor arranged to measure a change in capacitance at the surface of the body; and a processor arranged to determine that the object is in touch-contact, or has been thrown, based on the measured change in capacitance.
 2. A throwable object according to clause 1, wherein the processor is arranged to determine that the object is in touch-contact, or has been caught, when the capacitive proximity sensor measures a change in capacitance that equals or exceeds or falls below a predetermined threshold, or measures a change in capacitance that is inside a predetermined threshold range.
 3. A throwable object according to clause 2, wherein the predetermined threshold or threshold range is set to indicate that the object is in touch-contact because it is being held by a user or it has been caught, or to indicate that the object has been thrown because the object is no longer being held by a user.
 4. A throwable object according to any preceding clause, the body further housing a speaker and the speaker being arranged to emit a sound when the processor determines that the object is in touch-contact.
 5. A throwable object according to any preceding clause, the body further housing an inertial measurement unit (IMU), arranged to periodically measure travel data describing the motion of the object, wherein the processor is arranged to process the travel data depending on when the object is determined to be in touch-contact and/or to have been thrown.
 6. A throwable object according to any preceding clause, further comprising a throw sensor comprising at least one of an inertial measurement unit (IMU) and a barometric pressure sensor, the throw sensor arranged to periodically measure travel data describing the motion of the object, wherein: the travel data relates to one or more of the object's position, speed, height, acceleration, velocity, angular rate, roll, pitch, or yaw; and the processor is arranged to receive a travel data measurement from the throw sensor and determine that the object is in touch-contact, and/or that the object has been thrown, further based on a travel data measurement, or a difference between a current travel data measurement and a previous travel data measurement.
 7. A throwable object according to clause 6, wherein the processor is arranged to evaluate the travel data measurements from a time when the processor detects that the object has been thrown to a subsequent time when the processor detects that the object is in touch-contact so as to evaluate travel data describing the motion of the object during a throw.
 8. A throwable object according to clause 7, wherein the processor is arranged to determine a distance between a position of the object at a time when the object was thrown and a position of the object at a time when the object was in touch-contact based on the travel data measurements.
 9. A throwable object according to clause 7 or 8, wherein the processor is arranged to determine a maximum height of the object between a time when the object was thrown to a time when the object was in touch-contact based on the travel data measurements.
 10. A throwable object according to clause 9, wherein the maximum height is relative to a height of the object at the time when the object was thrown.
 11. A throwable object according to any of clauses 7 to 10, wherein the processor is arranged to count the number of full rolls or partial rolls the object makes during the throw based on the travel data measurements.
 12. A throwable object according to any preceding clause, wherein the body has a front end that faces forward when the object is thrown in a forward direction, wherein the front end is shaped to provide the least amount of air resistance against a forward motion of the object when the object is thrown with the front end facing in the forward direction, the throwable object further comprising a speaker facing away from the front end so as to direct sound in a backward direction that is substantially opposite to the forward direction.
 13. A throwable object according to clause 12, wherein the speaker is arranged to emit a sound when the processor determines that the object is in touch-contact.
 14. A throwable object according to clause 12 or 13, when dependent on any of clauses 4 to 8, wherein: the processor is arranged, during the throw, to determine whether a recent travel data measurement is different to a previous travel data measurement; and the speaker is arranged to emit a sound when the processor determines a difference.
 15. A throwable object according to clause 14, wherein the speaker is arranged to emit a sound when the processor determines a difference that exceeds or equals a predetermined threshold.
 16. A throwable object according to clause 14 or 15, wherein sound emitted by the speaker is different to an earlier sound emitted by the speaker prior to the processor determining the difference.
 17. A throwable object according to any of clauses 14 to 16, wherein the recent travel data measurement is the current travel data measurement from the IMU.
 18. A throwable object according to clause 17, wherein the previous travel data measurement is the most recent travel data measurement preceding the current travel data measurement.
 19. A throwable object according to any of clauses 3 to 18, wherein the IMU comprises an accelerometer, a gyroscope, and optionally a geomagnetic field sensor, arranged to provide travel data relating to one or more of the object's position, speed, height, accelerometer, velocity, angular rate, roll, pitch, or yaw.
 20. A throwable object according to any of clauses 6 to 19, wherein the barometric pressure sensor is arranged to measure the height of the object based on an atmospheric pressure measurement.
 21. A throwable object according to any of clauses 6 to 20, wherein the barometric pressure sensor comprises a temperature sensor, and is arranged to measure the height of the object based on an atmospheric pressure and temperature measurement.
 22. A throwable object according to any of clauses 12 to 21, wherein the body further comprises a major axis, and the speaker has a centre of mass that is substantially centred on the major axis.
 23. A throwable object according to any of clauses 12 to 22, wherein the body further comprises a back end opposing the front end, and the speaker is located within the back end, or adjacent to the back end.
 24. A throwable object according to clause 23, wherein the front end substantially curves towards the back end, and the back end is substantially planar.
 25. A throwable object according to clause 23 or 24, wherein the body further comprises a battery arranged to power the speaker, and a charging port, wherein the charging port is connected to the battery and located within the back end.
 26. A throwable object according to clause 25, wherein the speaker comprises a speaker cavity housing one or more of the battery, the capacitive proximity sensor, or the throw sensor.
 27. A throwable object according to clause 26, wherein the speaker cavity is a waterproof casing, or is defined by an internal chamber within the body.
 28. A throwable object according to clause 26 or 27, wherein the speaker cavity comprises a passive speaker membrane.
 29. A throwable object according to any of clauses 23 to 28, wherein the speaker cavity extends into the body, towards the front end.
 30. A throwable object according to clause 23 to 29, further comprising a fastener located at the back end of the body, wherein the fastener is arranged to removably connect the body to a tail.
 31. A throwable object according to clause 30, wherein the fastener is one of the group comprising a push-fit fastener, a bayonet fastener, or a screw-fit fastener.
 32. A throwable object according to clause 30 or 31, wherein the tail is one of a group of different tails, and the fastener may removably connect the body to any one of the group of different tails.
 33. A throwable object according to any of clauses 30 to 32, wherein the tail has a major axis that is collinear with a, or the, major axis of the body.
 34. A throwable object according to any of clauses 30 to 33, wherein the tail comprises a capping portion that is shaped to substantially cap the back end.
 35. A throwable object according to clause 34, wherein the capping portion comprises one or more apertures for the passage of sound waves emitted by the speaker.
 36. A throwable object according to any preceding clause, further comprising lift-generating fins extending radially from the body.
 37. A throwable object according to any of clauses 30 to 35 further comprising lift-generating fins extending radially from the tail.
 38. A throwable object according to clause 37, when dependent on clause 33, wherein: the tail comprises an elongate rod that is centred about, and extends along, the major axis of the tail; and the lift-generating fins extend radially from the elongate rod.
 39. A throwable object according to any of clauses 30 to 38, wherein the tail comprises a handle.
 40. A throwable object according to any preceding clause, further comprising a resilient outer body arranged to at least partially encase the body.
 41. A throwable object according to clause 40, wherein the resilient outer body comprises a shock absorbent foam.
 42. A throwable object according to any of clauses 5 to 41, the body further housing a transceiver arranged to transmit travel data and/or information relating to any of the determinations made by the processor.
 43. A throwable object according to clause 42, wherein the transceiver is arranged to wirelessly transmit the travel data and/or information relating to any of the determinations made by the processor using a short-range wireless communications protocol.
 44. A throwable object according to any of clauses 5 to 43, the body further housing a display arranged to display information relating to the travel data and/or information relating to any of the determinations made by the processor.
 45. A throwable object comprising: a body having a front end that faces forward when the object is thrown in a forward direction, wherein the front end is shaped to provide the least amount of air resistance against the forward motion of the object when the object is thrown with the front end facing in the forward direction; and a speaker facing away from the front end so as to direct sound in a backward direction that is substantially opposite to the forward direction.
 46. A throwable object according to clause 45, wherein the body further comprises a major axis, and the speaker has a centre of mass that is substantially centred on the major axis.
 47. A throwable object according to clause 45 or 46, wherein the body further comprises a back end opposing the front end, and the speaker is located within the back end, or adjacent to the back end.
 48. A throwable object according to clause 47, wherein the front end substantially curves towards the back end, and the back end is substantially planar.
 49. A throwable object according to clause 47 or 48, wherein the back end comprises a substantially planer face arranged to intersect the major axis.
 50. A throwable object according to any of clauses 45 to 49, wherein the front end has a three-dimensional shape substantially corresponding to a throwable ball such as a football or rugby ball.
 51. A throwable object according to clause 7 or 50, wherein the body further comprises a battery arranged to power the speaker, and a charging port, wherein the charging port is connected to the battery and located within the back end.
 52. A throwable object according to clause 51, wherein the speaker comprises a speaker cavity housing the battery.
 53. A throwable object according to clause 52, wherein the speaker cavity is a waterproof casing, or is defined by an internal chamber within the body.
 54. A throwable object according to clause 52, wherein the speaker cavity comprises a passive speaker membrane.
 55. A throwable object according to any of clauses 52 to 54, wherein the speaker cavity extends into the body, towards the front end.
 56. A throwable object according to clause 47 to 55, further comprising a fastener located at the back end of the body, wherein the fastener is arranged to removably connect the body to a tail.
 57. A throwable object according to clause 56, wherein the fastener is one of the group comprising a push-fit fastener, a bayonet fastener, or a screw-fit fastener.
 58. A throwable object according to clause 56 or 57, wherein the tail is one of a group of different tails, and the fastener may removably connect the body to any one of the group of different tails.
 59. A throwable object according to any of clauses 56 to 58, wherein the tail has a major axis that is collinear with a, or the, major axis of the body.
 60. A throwable object according to any of clauses 56 to 59, wherein the tail comprises a capping portion that is shaped to substantially cap the back end.
 61. A throwable object according to clause 60, wherein the capping portion comprises one or more apertures for the passage of sound waves from the speaker.
 62. A throwable object according to any of clauses 45 to 61 further comprising lift-generating fins extending radially from the body.
 63. A throwable object according to any of clauses 56 to 61 further comprising lift-generating fins extending radially from the tail.
 64. A throwable object according to clause 63, when dependent on clause 59, wherein: the tail has an elongate rod that is centred about, and extends along, the major axis of the tail; and the lift-generating fins extend radially from the elongate rod.
 65. A throwable object according to any of clauses 59 to 64, wherein the tail comprises a handle.
 66. A throwable object according to any preceding clause, further comprising a resilient outer body arranged to at least partially encase the body.
 67. A throwable object according to clause 66, wherein the resilient outer body comprises a shock absorbent foam.
 68. A throwable object according to any of clauses 45 to 67, wherein the throwable object takes the form of a shuttle, ball, football, projectile, torpedo, or vortex football.
 69. A kit comprising a body and multiple different tail portions that can be interchangeably connected to the body to form multiple different throwable objects.
 70. A kit according to clause 69, wherein: the body has a front end that faces forward when the object is thrown in a forward direction, the front end being shaped to provide the least amount of air resistance against the forward motion of the object when the object is thrown with the front end facing in the forward direction; and a speaker facing away from the front end so as to direct sound in a backward direction that is substantially opposite to the forward direction.
 71. A kit according to clause 69 or 70, wherein the body further comprises a major axis, and the speaker has a centre of mass that is substantially centred on the major axis.
 72. A kit according to any of clauses 69 to 71, wherein the body further comprises a back end opposing the front end, and the speaker is located within the back end, or adjacent to the back end.
 73. A kit according to clause 72, wherein the front end substantially curves towards the back end, and the back end is substantially planar.
 74. A kit according to clause 72 or 73, wherein the back end comprises a substantially planer face arranged to intersect the major axis.
 75. A kit according to any of clauses 69 to 74, wherein the front end has a three-dimensional shape substantially corresponding to a throwable ball such as a football or rugby ball.
 76. A kit according to clause 72 or 75, wherein the body further comprises a battery arranged to power the speaker, and a charging port, wherein the charging port is connected to the battery and located within the back end.
 77. A kit according to clause 76, wherein the speaker comprises a speaker cavity housing the battery.
 78. A kit according to clause 77, wherein the speaker cavity is a waterproof casing, or is defined by an internal chamber within the body.
 79. A kit according to clause 78, wherein the speaker cavity comprises a passive speaker membrane.
 80. A kit according to any of clauses 77 to 79, wherein the speaker cavity extends into the body, towards the front end.
 81. A kit according to clause 72 to 80, further comprising a fastener located at the back end of the body, wherein the fastener is arranged to removably and separately connect the body to each of the multiple different tail portions.
 82. A kit according to clause 81, wherein the fastener is one of the group comprising a push-fit fastener, a bayonet fastener, or a screw-fit fastener.
 83. A kit according to any of clauses 81 to 82, wherein one or more of the tail portions comprise a major axis that is collinear with the major axis of the body, when connected together.
 84. A kit according to clause 83, wherein one or more of the tail portions comprises a capping portion that is shaped to substantially cap the back end.
 85. A kit according to clause 84, wherein the capping portion comprises one or more apertures for the passage of sound waves from the speaker.
 86. A kit according to any of clauses 69 to 85, further comprising lift-generating fins extending radially from the body.
 87. A kit according to any of clauses 83 to 86, wherein one or more of the tail portions further comprises lift-generating fins extending radially from the tail portion.
 88. A kit according to clause 87, wherein: the tail portion has an elongate rod that is centred about, and extends along, the major axis of the tail portion; and the lift-generating fins extend radially from the elongate rod.
 89. A kit according to any of clauses 83 to 88, wherein one or more of the tail portions comprises a handle.
 90. A kit according to any of clauses 69 to 89, the body further comprising a resilient outer body arranged to at least partially encase the body.
 91. A kit according to clause 90, wherein the resilient outer body comprises a shock absorbent foam.
 92. A kit according to any of clauses 69 to 91, wherein the body houses: a capacitive proximity sensor arranged to measure a change in capacitance at the surface of the body; and a processor arranged to determine that the object is in touch-contact, or has been thrown, based on the measured change in capacitance.
 93. A kit according to any of clauses 69 to 91, wherein the body houses a throw sensor comprising at least one of an inertial measurement unit (IMU) and a barometric pressure sensor, the throw sensor arranged to periodically measure travel data describing the motion of the object.
 94. A kit according to clause 93, wherein the IMU comprises an accelerometer, a gyroscope, and optionally a geomagnetic sensor, arranged to provide travel data relating to one or more of the object's position, speed, height, acceleration, velocity, angular rate, roll, pitch, or yaw.
 95. A kit according to any of clauses 93 to 94, wherein the barometric pressure sensor is arranged to measure the height of the object based on an atmospheric pressure measurement. 